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Chain-Breaking Phen...
Chain-Breaking Phenolic 2,3-Dihydrobenzo[b]selenophene Antioxidants : Proximity Effects and Regeneration Studies
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- Singh, Vijay P. (författare)
- Uppsala universitet,Organisk kemi,Centre of Advanced Studies in Chemistry, Panjab University, India
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- Yan, Jiajie (författare)
- Uppsala universitet,Organisk kemi,Lars Engman
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- Poon, Jia-fei (författare)
- Uppsala universitet,Organisk kemi,Lars Engman
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- Gates, Paul J. (författare)
- School of Chemistry, University of Bristol, United Kingdom
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- Butcher, Ray J. (författare)
- Department of Chemistry, Howard University, USA
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- Engman, Lars, 1952- (författare)
- Uppsala universitet,Organisk kemi
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(creator_code:org_t)
- 2017-10-09
- 2017
- Engelska.
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Ingår i: Chemistry - A European Journal. - : Wiley. - 0947-6539 .- 1521-3765. ; 23:60, s. 15080-15088
- Relaterad länk:
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https://research-inf...
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https://urn.kb.se/re...
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https://doi.org/10.1...
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Abstract
Ämnesord
Stäng
- Phenolic 2,3-dihydrobenzo[b]selenophene anti-oxidants carrying the OH-group ortho (9), meta (10, 11) and para (8) to the Se were prepared by seleno-Claisen rearrangement/intramolecular hydroselenation. Meta-isomer (11) was studied by X-ray crystallography. The radical-trapping activity and regenerability of compounds 8-11 were evaluated using a two-phase system where linoleic acid was undergoing peroxidation in the lipid phase while regeneration of the antioxidant by co-antioxidants (N-acetylcysteine, glutathione, dithiothreitol, ascorbic acid, tris(carboxyethyl)phosphine hydrochloride) was ongoing in the aqueous layer. Compound 9 quenched peroxyl radicalsmore efficiently than α-tocopherol. It also provided the most long-lasting antioxidant protection. With thiol co-antioxidants it could inhibit peroxidation for more than five-fold longer than the natural product. Regeneration was more efficient when the aqueous phase pH was slightly acidic. Since calculated O-H bond dissociation energies for 8-11 were substantially larger than for α-tocopherol, an antioxidant mechanism involving O-atom transfer from peroxyl to selenium was proposed. The resulting phenolic selenoxide/alkoxyl radical would then exchange a hydrogen atom in a solvent cage before antioxidant regeneration at the aqueous lipid interphase.
Ämnesord
- NATURVETENSKAP -- Kemi -- Organisk kemi (hsv//swe)
- NATURAL SCIENCES -- Chemical Sciences -- Organic Chemistry (hsv//eng)
Nyckelord
- chain-breaking antioxidants
- phenols
- dihydrobenzoselenophenes
- lipid peroxidation
- co-antioxidants
- Chemistry with specialization in Organic Chemistry
- Kemi med inriktning mot organisk kemi
Publikations- och innehållstyp
- ref (ämneskategori)
- art (ämneskategori)
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